Lifting jack



May 6, 1930. i l. K. HOTT V 1,757,249

LIFTING JACK Filed .Sept 18, 1924 4 Sheet s-S h eet 1 INVENTOR Jan 144. 6 077 ATTORNEY May 6, 1930. I. v. K. HQTT 1 157,249

LIFTING JACK Filed Sept. 18, 1924 4 Sheets-Sheet 2 k h i i I INVENTOR 4 I j b l- K1907? AB-Y ATTORNEY May 6, 1930; l. v. K. HOTT 1,757,249

LIFTING JACK Filed Sept. 18, 1924 4 Sheets-Sheet 4 2 b G k it b h m (9 I) .36, i Q Q 3 Q L\ \B b ATTO RNEY Patented May 6, 1930 1 UNITED STATES ION v. K. norm, or 'nAYromonIo, ASSIGNOR TO rrnn .ToYcE-cnrnnann COMPANY, or DAYTON, 01110, a CQRPORATION or OHIO PATENT OFFICE LIFTING J'AGK Application filed September 18, 1924. Serial No. 738,555.

This invention relates to lifting jacks and more particularly to lifting jacks of what is known as the self-lowering type,-in which the load is allowed to move downwardly under its own weight but this lowering movement is regulated by suitable controlling apparatus. r

One object of the invention is to provide an improved self-lowering jack in which the lowering of theload may be positively con trolled. a

A further object of the invention is to provide a self-lowering jack which may be power operated either to raise the load or to lower the same; and which may also. be operated by hand either to raise the load or to permit the same to be lowered.

A further object of the invention is to provide such a jack withan improved retarding device for controlling the downward movement-of the load, which will be ofsuch a character that it willnot vresist the operation of the mechanism to elevate the .lo'ad.

Other objects of the invention willappear as the mechanism is described in detail. j a

In the accompanying drawings Fig. '1 is a side elevation of a jack embodying my invention, showing the motor attached thereto; Fig. 2 is a vertical sectional view taken on the line 2-2'0f Fig. 5; Fig. 3 is a transverse sectional View taken on theline 3-3 of Fig. 2; Fig. 4 is a section taken on the 1ine44 of Fig. 3; Fig. 5 is a section taken on the line 5-5 of Fig. 1; and Fig. 6 is a section taken on the line 66 of Fig. 4.

In these drawings I have illustrated one embodiment of my invention and have shown the same as applied to a screw operated jack in which the screw is held against vertical movement, but it will be understood that the invention may be applied to' jacks of various kinds and may take various forms.

In that particular embodiment here shown I 6 the outer surface of'the rain. The ram I is provided near its lower end with a nut 7 which is held against rotation therein and, in the present instance, is provided'on its opposite sides with lugsr8 which extend into slots 9 in the lower portion of the ram.

Threaded in the nut 7 is a lifting screw 10 which is rotatably mounted on the base 1. The pitch of the screw is such that when unrestrained the weight of a load on the ram 3 will cause the nut to travel downwardly on the screw and thus lower the load. A spring pressed dog llmounted in the upper portion of the standard 2 is arranged to enter a notch 12 in the lower portion of the ram to check lar ball race in a bearing plate 15 mounted on the base 1, and bearing balls 16 are mounted in theseball races to facilitate the rotation of the screw, it being noted that the stem of the screw is journaled in a bearing formed in the bearing plate 15. The Worm wheel 13 meshes with a worm 17, the shaft 18 of which is journaled in bearings 19 and 20 formed in a laterally extending portion of the housing forming a part of the base 1. The pitch of this worm is such that it may be rotated by the worm wheel when the latter is actuated by the downwardmovement of the load.

The worm 17 is connected with suitable driving mechanism and with suitable retarding devices which may either regulate or en- 'tirely prevent the rotation of the worm by the downward movement of the load. In the present arrangement the retarding devices are in part interposed between the worm and the driving mechanism for elevating the load. The retarding devices consist in part of a ..worm wheel 21' which is connected with the shaft of the worm 17 and which meshes with a worm 22 on a vertical shaft 23 journaled in bearings 24: and 25 in a housing 26 rigidly secured to the base. The pitch of the worm 22 may be such as to completely lock the worm 17 against rotation or it may be such that it may be rotated by the worm wheel 21 when the latter is rotated by the downward movementof the load. The worm 22 is connected with the driving mechanism and the worm wheel 21 is connected with; the shaft of the worm 17 in such a manner that therotation of the worm wheel 21 by the worm 22 will cause the worm 17 to be rotated in a direction to elevate the load, and when the worm 17 is rotated by the downward movementofthe load this movement will be transmitted to the worm wheel 21,and the'connection is preferably in the formof a one-way clutch which will permit the worm 17 to be rotated in a direction to elevate the load independ-- ently of the worm wheel'21, as by meansof a manually operated device, such as shown in Fig. 3. As there shown, the shaftl8 of'the worm 17 extends beyond the bearing 19 and has rigidly securedthereto a vratchet wheel 27 with which cooperates a pawl carried by a pawl carrier 28 journaled on the shaft, and provided with a lever socket 29 adapted to receive a lever by means of which the pawl and ratchet mechanism may be actuated to rotate the shaft and the worm 17. The oneway clutch may take various forms but I have here shown it as comprising a clutch member 30 rigidly secured to the shaft 18 between the worm wheel 21 andthe bearing 20 and provided on its outerface with an annular series of ratchet teeth 31. The worm wheel 21is provided in its inner face with an annular series of recesses 32 in each'of which is I slidably mounted a plunger or pawl 33 which is pressed inwardly into engagement with the ratchet teeth 31 byv a spring 34, the arrangement on the ratchet teeth and the pawls being such that when the worm 17 is rotated manually to elevate the load the ratchet teeth will rode overthe pawls, thus permitting the worm to rotate relatively to the worm wheel, but when the worm 17 is rotated by the clownward movement of the load the ratchet teeth will pick up the pawls and cause the worm wheel 21 to rotate with the worm 17 The retarding device further consists of a brake or friction controlled device arranged to resist the movement of the worm 22 by the worm wheel 21. In the present construction 'this brake is of a multiple disk type and comprises a series of frlction disks 35 mounted wheel 21 is rotated by the downward movement of the load the teeth thereof will act on the spiral of the worm 22 with a downward thrust and will thus cause the friction disks to be pressed into firm frictional engagement one with the other so that the brake will function to resist the rotation of the worm 22, but when the worm 22 is rotated to actuate the worm. wheel and thus permit the downward movement of the load the action of the spiral worm on the teeth of the worm wheel will tend to lift the worm and the shaft 23 and thus relieve the friction on the disks and permit the worm to turn freely.

The driving mechanism for operating the actuating means for the lifting screw may take various forms and, as here shown, it consists of a gear 39 connected with the vertical shaft 23 and meshing with a pinion 49 mountedon a shaft 41 and having connected therewith a second gear 42 which in turn meshes with a pinion 43 secured to a vertical shaft 44, the shaft 41 and 44 being journaled in suitable hearings in a housing 45 which encloses the gear train. Suitable means are provided for connecting with the gear train a portable motor whereby the driving mechanism may, when desired, be

In the devicehere shown power operated. the shaft 44: has its upper end projecting above the housing 45, as shown at 16, and this projecting end of the shaft is squared or non-circular in shape and adapted to enter a socket 17, on the lower end of the shaft of a motor 48, wherebythis motor may be quickly and easily connected with or disconnected from the gear train by merely placing the socket in engagement with or removing the same fro'mthe end of the shaft 44.. If desired,the standard 2 may be provided with a yoke'or U-shaped bracket 19 arrangedto receive one of the horizontal handles 50 of the motor and to support the same in an upright position on the shaft 44. It will be understood that the motor 48 may be of any suitable character but it is preferably either an electric motor or an air driven motor.

The gear train or driving mechanism is preferably connected with the vertical shaft i 23 in such a manner that when it is operated to elevate the load it will impart a V 5 slight upward movement to the shaft 23 and.

thus disengage the friction disks and release the'brake so that the latter will not resist the operation of the shaft;

To this end the shaft 23 is so mounted in its bearings that it may have a slight vertical movement and 'the gear 39 is rigidly secured to a hub or sleeve 51 which is mounted about the shaft and is so connected therewith that the rotation of the gear 39 in one direction will impart an upward movement to the shaft, this being preferably accomplished by providing the hub with an inclined slot 52 into which means which are seated in a ball race formed in the upper end of the'bearing 25. It will be apparent therefore that when the motor is operated inadirection toelevate the load the shaft 23 will first be elevatedslightly to release the brake and the worm 22 will then rotate the worm wheel 21 and this movement will be transmittedthrough the worm 17 and worm wheel 13 to the elevating screw. Then the motor is operated in a reverse direction the worm 22 will drive the. worm wheel 21 in a reverse direction which will permit the worm 17 to be rotated by the downward movement of the load, thereby permitting the load to be lowered under its own weight. v It will be understood that the driving mechanism or driving gears may be of any suitable character and number but inas much as the present device contemplates the use of a relatively high speed motor I have provided amore or. less'extended train of reducing gearing so tliat'the speed of the motor maybe properly reduced before it reaches the worm 22. g

As has been stated the worm 22 may be rotated in a directionto permit the load to be lowered under its 'own weight either by the action of the motor or through suitable manually operated devices. The manually operated devices may take any suitable form. In the present instance, I have secured to the upper end of the vertical shaft 23 a beveled pinion 55 which is preferably sonnected with the shaft by means'of a'pin extending through a transverse slot 57 in the shaft so that the latter can'have a limited vertical movement with relation to the pinion. Meshing with the pinion is a second beveled pinion 58 whch is rotatably mounted in a suitable bearing 59 in a-housing 60 which encloses the gears. Means are provided for rotating the beveled gears to actuate the shaft 23 but this rotating means is normally disconnected from the gears so that" the latter may rotate freely when the shaft is driven by the motor. Preferably an actuating shaft 61 is mountedin bearings 62 and63 in housing 60 for bothrotatoryand axial movement and extends loosely through the beveled gear 58 so that this gear, may rotate thereon. The shaft is provided with a projection or pin 64 adapted to enter a recess 65 in'the hub of the gear 58 when the shaft is forced inwardly and thereby connect the shaft with thegear to cause the sition in which will be disconnected from the gear.

VVhileI have shown and described one embodiment of my invention I wish it to be understood that I do not desire to be limited tdithe details thereof as various modifications may appear'to a person skilled in the art.

- 'Having now fully described my invention, what I claim as new and desire toisecure'by Letters Patent, is

1; In a lifting ack, a base, a lifting screw, supported by said base, means for actuating said screw, said actuating means being of such a character that the load onsaid lifting screw may move downwardly under its own weight, means for retarding said downward movement of the load,and a main driving mechanism for said lifting screw, said driving mechanism operable in one direction to operate the actuating means to cause the lifting screw to elevate the load thereon and operable in the other direction to operate said ret-arding'means to permit said downward movement of the load.

2. In a lifting jack, a base, a lifting screw supported by said base, means for actuating said screw, said actuating means being of such a character that the load on said lifting screw may move downwardly under its own 3. In a lifting jack, a base, a lifting screw,

sup orted by said base, means for actuating sai'c screw, said actuating means being of such a character that the load on said lifting screw may move downwardly under its own weight, means for retarding said downward movement of the load, and driving mechanism comprising reducing gearing operable in one direction. to operate the actuating means to cause said lifting screw to elevate the load thereon and operable in another direction to operate said retarding means to permit said downward movement of the load, and means for detachably connecting a motor with said reducing gearing.

4. In a lifting, jack, a base, a lifting screw supported by said base, means for actuating said screw, said actuating means being of V such a character that the load on the lifting screw may move downwardly under its own operate the actuating 'meansto cause said lifting screw to elevate the load thereon and operablein' another direction to operate said retarding meansto permit the downward movement of the load. V 1 a 5. In a lifting jack, a base, a lifting screw supported by said base, means for actuating said screw, said actuating means being of screw will move downwardly under its own weight, a worm wheel connected with said actuating means, a worm meshing with said worm wheel and adapted torotate said worm fwheel, to cause the load on said screw tobe elevated, and to be rotated by said worm wheel, a friction device connected with said worm and so arranged that the friction thereon will be relieved when said wormis rotated to actuate said worm wheel, and a main driving mechanism for said liftingscrew connected with said worm.

7. In a lifting jack, a base, a lifting screw supported by said base, means for actuating said screw, said actuating means being of such a character that the load on said lifting screw will move downwardly under'its own weight, a. worm wheel connected with said actuating means, a worm meshing with said worm wheel and adapted torotate said worm wheel, to cause the load on said screw to be elevated, and to be rotated by said worm wheel, a friction device connected with said worm and so arranged that the friction thereon will be relieved when said worm is rotated to actuate said worm wheel,'driving mechanism for said worm, and means actuated by said driving mechanism for relieving the friction on said friction device.

8. In a lifting jack, abase, a lifting screw supported by said base, means for actuating said screw, said actuating; means being of such a character that the load on said lifting screwwill move downwardly under its own weight, a worm wheel connected with said actuating means, a worm meshing with said .worm wheel and adapted to rotate said worm wheel, to cause the load on saidscrew to be elevated, and to be rotated by said worm wheel,"a friction device connected with said worm, driving mechanism for rotating said worm and causing the loadto be elevated, and means actuated by said driving mechanism to relieve the friction on said friction device. v

9. In a lifting jack, abase, a lifting screw supported by said base, means for actuating said screw, said actuating means being of such a character that the load on said liftingscrew will move downwardly under its own weight, a worm wheel connected with said'actuating means, a shaft capable of axial movement, a worm carried by said shaft and meshing with said worm wheel and adapted to be rotated thereby when said load moves downwardly, a multiple disk brake connected with said shaft, amain driving mechanism for rotating said shaft in one direction to causethe load to be elevated and in a reverse direction to permit theload to bel'o'wered, and means controlled by the rotation of said shaft for imparting axial movement to said shaft when it is rotated in'the first mentioned direction.

. 10. In a lifting jack, a base, a lifting screw supported by said base,fmeans for actuating said screw,said actuating means being of such a character that the load on said lifting screw will move downwardly under its own weight, a worm wheel connected with said actuatingmeans, a shaft capable-of axial movement, a worm carriedby said shaft and meshing with said worm wheel and adapted to be rotated thereby. when said load moves downwardly, a multiple disk brake connected with said shaft,imeans for'rotating said shaft in one direction to' cause the load'to be elevated and in a reverse direction to perm'it'the load to be lowered, said multiple disk brake being so arranged that the action of said lUlB worm and said worm wheel, when the-worm is rotated in the last mentioned direction, will tend to separate the disks of said brake.

11. In a lifting jack, a base, a lifting screw supported by said base, means for actuating said screw, said actuatingmeans being of such a character that theload on said lifting screw may move downwardly under its own weight, a worm wheel connected with said actuating means, a shaft capable of axial movement, a worm carried by said shaft and meshing with said worm wheel and adapted to be rotated thereby when said load moves downwardly, gearing connected with said shaft for rotating the same in either direction, means for actuating said gearing. and

means controlled by said gearingfor im-' parting axial movement to said shaftto release said brake when said gearing is actuated in either direction.

12. In a lifting jack, a base, a lifting screw supported by said base, means for actuating said screw, said actuating means being of such a character that the load on said lifting screw will move downwardly under its own weight, a worm wheel connected with said actuating means, a shaft capable ofaxial movement, a brake controlled bythe' axial movement of said shaft, a worm carried by actuating means, a shaft capable of axial V saidload to be' lowered.

movement, a worm carried by said shaftand meshing with said worm wheel and adapted to be rotated thereby when said load moves downwardly, a gearfor rotating said shaft, a connectionbetween said gear and said shaft to cause the rotation of said gearto impart axial movement to said shaft, andmeans for actuating said gear.

14. In a lifting jack, a base, a lifting screw supported bysaid base, means for actuating said screw, said actuating means; being of such a character that the load on said lifting screw may move downwardly under its own weight, a worm wheel connected with said actuating means, a shaft capable of;,axial movement, a wormcarried by said shaft and meshing with said worm wheel, and adapted to be rotated thereby when said load moves downwardly, a sleeve mounted'on said shaft having an inclined slot, a gear rigidly secured to said sleeve, means for rotating said gear, and a pin. on said shaft extending into said slot.

15. In a lifting jack, a base,'a lifting screw supportedby said base, means for actuating said .liftingiscrew, said actuating means being of such a character that the load lonfsai'd lifting screw may move. downwardly under its own welght, a worm wheel connected with said actuating means, afsha'ft, a worm carried by said shaft and meshing with saidworm wheel, power operated means to rotate said worm inafdirectio'n to cause said'load to be elevated, and manually operated means to rotate saidfworm in a direction to permit 16. In a lifting j ack, a base, a lifting screw upported by} said base, means for" actuating said lifting-screw,"said actuating means being of such a character that the load on said lifting screw may move downwardly underits own weight, a worm wheel connectedwith said actuating means,'a shaft, a'worzii carried by said shaft and meshing with said'worni wheel, a train of gearing connected with said shaft, means for detachably connecting a motor with said train of gearing, and manually operated means connected with said 7 shaft for rotating the same independently of said motor,

: :17. urang-j c a' bhs iaiiigl ii supportedlby said base, means for, a tuat ng said lifting screw, said actuating means being of such a character that the load on said l fting screw may move downwardly under.

its own weight,a wormwheel connected with 7 said actuating means, a shaft, a worm carried by sald shaft and meshmg with saldiworm wheel, atrain of gearing connected with said own weight, a 'wormwheelconnected with sand actuating means, ashaft, a worm car-,

ried byfsa'id' shaft and meshing with said worm wheel, a gear connected with said shaft, means for detachably connecting a motor with said gear, a beveled ear secured to said shaft, a second bevele gear meshing with the first mentioned beveled gear, a shaft normally disconnected from said seconcl beveled gear but movable into and, out of operative relation thereto, and means for operating said shaft. I

19. In a lifting jack, a base, 'a lifting screw supported by said base, means for actuating said screw to elevate the load, said actuating means being of such a character that the load on said-lifting screw will move downwardly under; its own weight, a worm wheel, a oneway clutch connecting said worm wheel with said actuatin'gmeanaa worm meshing with 7 said worm wheel, and a main driving mechanism] fo'r 'rotating said worm in, one direction to liftf'the load on said screw and inthe other direction'to permit the load to move downwardly under its own weight.

. V 20. alifting'jack, a base, a'lifting screw supported by SillCl base, means'for actuating said screw to "elevate the "load, 'said actuating means 'being'of such a character that the load on saidlifting screw will move downwardly under its own, weight, a worm wheel, a one- Wayclutcl connecting said worm wh'eel'with saiaabaiatmgmeans, a worm meshing with said worm wheel, driving means for rotating ,saidworm in one'direction to lift the load onfsaid screwandin' the otherdirection to permit the load to 7 move downwardlyfnnder its own weight and -means for detachably connectlngi saldrotatmg means wlth" amotor.

* ,QQLIInVa ,lifting ack, afbase, a; l-iftingscrew' 7 wheel, power operated means for rotating said worm in either a forward direction or in a reversed direction, and manually operated means to rotate the worm in a reverse direction. i V

22; In alifting jack, a base, a lifting screw, snpported'by said base', 'means for actuating said screw, said actuating means being of such a character that the loadon said lifting screw may move downwardly under its own weight, a worm wheel, a one-way clutch connecting said worm wheel with said actuating means, a worm meshingwith said worm wheel, power operated means for rotating said worm in a direction to operate said actuating means, and other means for rotating said worm in a reverse direction to permit the downward movement of said load.

23. a lifting jack, a base, a lifting screw supported by said base, a worm wheel secured to said liftingscrew, a worm meshing with said worm wheel and adapted to be rotated thereby when the load moves downwardly, a

second worm wheel connected with said worm, a second worm meshing with said second worm wheel, manually operated means for rotating said secondworm, and means for detachably connecting a motor with said second worm. V

24.. In a lifting jack, abase, a lifting screw supported by said base, a worm wheel secured to said lifting screw, a worm meshing with said worm wheeland adapted to be'rotated thereby when the load moves downwardly, a second worm wheel connected with said worm, a second worm meshing with said sec ond worm wheel, a train of gearing connected with saidsecond worm, a shaft secured to one gear of said train and having means for detachably connecting the same with a motor,

and a manually operated device'connected with said worm.

25. In a lifting j ack,a base, a lifting screw supported by said base,a worm wheelsecured to said lifting screw, a worm meshing with said worm wheel and adapted to be rotated thereby when the load moves downwardly, a second worm wheel connected with said worm, a second worm meshing with said second worm wheel, a multiple disk brake con-V nectedwith said-second worm,"said second worm being capable of axial movement to control the friction on said brake, driving mechanism for said worm, and means actuated by said driving mechanism to impart axialmovement to said worm. I

26. In a lifting jack, a base, alifti'ng screw supported by said base, a worm wheelsecured to said lifting screw, a worm meshing with said worm wheel and adapted to be rotated thereby, manually operated means con nected with saidworm for rotating the same,

sec'ondfworm .wheel, a one-way clutch connection between said second worm wheel and said worm, a second worm meshing with said supported by said base, a worm wheel secured to said lifting screw, a worm meshing with said worm wheel and adapted to be rotated thereby, manually operated means connected with said worm for rotating the same, a second worm wheel, a one-way clutch connection between said second worm wheel and said worm, a shaft, a second worm carried bysaid shaft and meshing with said second worm wheel, a gear train connected withsaid shaft and having means for detachably connecting the same witha motor, and manually operated means connected with 'said shaft for operating the same independently of said motor; r

28. In a lifting jack,abase, a lifting screw supported by said base, a worm wheel secured to said lifting screw, a worm meshing with said worm wheel and adapted to be rotated thereby,v1nanually operated means connected with said worm for rotating the same, a sec-. ond worm wheel, a one-way clutch connection between said second W0rm wheel and said worm,a shaft capable of axial movement, a second wormcarried by said-shaft, meshing with said' second worm wheel and adapted to be rotated thereby, a plurality of friction disks secured to said shaft, other friction disks mounted independently of said shaft and interleaved between the first men tioned disks, driving gearing operatively connected with said shaft for rotating the same in either direction, and means actuated by said driving gearing for imparting axial movement to said shaft. t T 29. In a lfting ac'k,a' base, a lifting screw supported by said base, a worm wheel secured" to said lifting screw, a worm meshing with.

saidworm wheel and adapted to be rotated thereby, manuallyoperated means connected with said worm for rotating the same, a second worm wheel, a one-way clutch connection between said second worm wheel and said worm, a shaft capable of axlal movement, a

second worm carried by said shaft, meshing a with said second worm wheel and adapted to v be rotated thereby, a plurality of friction V disks, secured to, said shaft, other friction disks mounted independently of said shaft and interleaved between the first mentioned at I disks, and means for rotating said shaft and r I said worm in either direction. a V a 30. In a liftingjack, a base, a lifting screw supported by said base, a worm wheel secured to said lifting screw, a shaft,:a worm secured 'to said shaft, meshing with said'worm wheel and adapted to berotated thereby, a manually operated device connected with said shaft for rotating said worm, a clutch member rigidly secured to said shaft and having on one face thereof an annular series of ratchet teeth, a second worm wheel rotatably mounted on said shaft and having on that face adjacent to said clutch member an annular series of recesses, spring pressed pawls slidably mounted in said recesses to engage the ratchet teeth of said clutch member, a

second worm meshing with said second worm wheel, and means for rotating said second worm.

31. In a lifting jack, a base, a lifting screw supported by said base, a worm wheel secured to said lifting screw, a shaft, a worm secured to said shaft, meshing with said Worm wheel and adapted to be rotated thereby, a manually operated device connected with said shaft for rotating said worm, a clutch meme berrigidly secured to said shaft and having on one face thereof an annular series of ratchet teeth, a second worm wheelrotatably mounted on said shaft and having on that face adjacent to said clutch member an annular series of recesses, spring pressed pawls slidably mounted in said recesses to engage the ratchet teeth of said clutch member, a second worm meshing withsaid second worm wheel, a multiple disk brake connected with said second worm, and means for rotating said second worm and releasing said brake.

In testimony whereof, I affix my signature hereto.

ION V. K. HOTT. 

